Hydraulic press.



' B. GERDAU.

HYDRAULIC PRESS. APPLICATION rum) 00111 1e99.f

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' PATENTED FEB. 5, 1907.

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B. GERDAU.

HYDRAULIC PRESS. APIILIGATION FILED 00111, 1899.

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z SHEETS-SHEET BERTHOLD GERDAU, OF DUSSELDORF, GERMANY.

HYDRAULIC PRESS.

Specification of Letters Patent.

Patented Feb. 5, 1907.

Application filed October 11, 1899. Serial No. 733,241. I

To ail whom it may concern:

Be it known that I, BERTHOLD GERDAU, a subject of the King of Prussia,residing at Dusseldorf, in the Kingdom of Prussia, Germany, haveinvented certain new and useful Improvements in Hydraulic Presses, ofwhich the following is a s ecification.

This invention as reference to hydraulic presses, and applies inparticular to those wherein the pressure of the working piston may beincreased by an auxiliary plunger acting upon said working piston andintensifying the pressure produced thereby; and it further comprisesimprovements in the means of delivering and distributing the water,whereby a great economy is realized and the highest degree of efficiencysecured.

In the accompanying drawings, Figure 1 is a front elevation, partly insection, of my improved press; Fig. 2, a plan thereof, partly insection; Fig. 3, a horizontal section on line 3 3, Fig. 1 and Fig. 4, adetail of the valve.

The press is composed of a suitable number of pistons c f g, working,respectively, in the cylinders b c d, secured Within the frame a of thepress, which is filled with pressure- Water from the pipe y. Thepressure-ram is attached to the cross-head h, to which is rigidlyconnected the middle piston f, while the lateral pistons e and g areseparate from the said cross-head h and rest upon it by a balland-socketconnection, which afiords greater security against lateral oscillationof the whole system. The cross-head h slides up and down on fourguide-rods i, penetrating through suitable openings of the cross-head.

76 lm are pressuf-intensifiers, consisting of plungers of across-section smaller than that of the pistons e f g and sliding withinthe secondary cylinders 2 3 4, arranged above cylinders b c d,respectively. The lower extremities of the plungers enter directly thecylinders I) c (1, respectively, which are filled with pressure-water orsome other liquid under pressure from the pipe y, as above indicated.This pressure-water constitutes an incompressible medium fortransmitting multiplied pressure from the plungers Z m to the top of thepistons e f g, respectively. Pistons 5 6 7 are attached to the upperextremities of the plungers, upon which live steam may be made toimpinge, the steam being admitted to the top of the cylinders by theports 8, 9, and 10. Suitable valves (not shown in the drawings) areprovided which allow the steam to be admitted to only some or all ofthese cylinders at a time in the well-known manner. Correspondingregulating valves (not shown) are inserted into the water-deliveringpipes to admit water to either one or all of the press-pistons efg.Additional pistons 11, which I will call withdrawal or return pistons,are secured upon the sides of the cross-head or follower hand working inthe cylinders n, arranged on each side of the press, operate to withdrawthe press-pistons at the completion of their strokes.

0 is an air-vessel or a vessel filled with some other elastic fluidinserted into the pressurewater conduit 8, which leads to theretunncylinders n. A-check-valve q, inserted into conduit 8, serves toprevent return of water from pipe .9 to pipe 2 whenever pressure in pipe8 in the operation of the press becomes greater than accumulator or tankpressure.

The valve p is connected with inlet pipe or conduit g, which serves fordelivering the pressure liquid on top of the pistons e f g. The valve 19is constructed in the manner of the ordinary hydraulic valves,comprising a series of collars or sleeves on the valve-stem which bysuitable annular channels and passages establish communication with andbetween the pipes s 'y 90. The exhaust-water is discharged through pipe90, communicating with the regulating-valve p by the conduit to, betweenwhich and ipe 00 I insert a springpressed throttling-vive 1', whichoperates to maintain a certain pressure of water inthe system, whichwill hold the plungers 7c Z m and the steam-pistons 5 6 7 in a raisedposition. This valve is depressed by the water displaced upon the ascentof the press pistons, which is then delivered into the discharge-pipe x.Pressure-water for refilling is admitted through the pi e 2.

The operation is as foil the pressure-cylinders with water, the pipe 2,coming from a suitable pressure-tank, is connected to pipe y by movingvalve 19 in the proper direction. After bar h has been brought down uponthe work-piece valve 2') is closed and steam is admitted above thepistons 5 6 7. Upon the descent of the press-plungers and of the pistons5 6 7 a high tension is produced in the pressure-storer 0, which isfilled with compressed-air by the water displaced in thewithdrawahcylinders n, this tension operating on the release of thepress to withdraw the press-pistons e f g. The water displaced in thewithdrawal-cylinders during the preliminary lowering of pisoWs: In orderto fill tons e f g flows through the pipe 8 and the valve p, which isopened during this time, into the pipe 1 which delivers it into any orall of the pressure-cylinders on the top of the pistons e f 9. After thepress has performed its work and the pistons e f g are to be re turnedpipe y is connected to the exhaustpipe to by proper movement of valve p,whereupon the air-pressure within the pressure-storer 0 starts tooperate the withdrawal-cylinders n. According to the expansion of thefluid within the chamber 0 the pressure therein will decrease until thepressure within pipe 2 will lift valve 9 and permit pressure-water fromthe tank to enter pipe 8, so as to fully operate thewithdrawalcylinders, Fig. 2. The water which has been displaced in thepressure-cylinders upon the upward stroke of the pistons is deliveredthrough the open valve 19 into the exhaustpipe w, where it depresses thevalve 1' and is discharged through pipe 11;. It is obvious that inasmuchas I may have the steam act upon any or all of the piston-heads 5 6 7and also fill any or all of the cylinder-heads b a (Z withpressure-water I am enabled to obtain any variation of pressure withoutinterfering in the least with the uniformity of the strokes or with theuniformity of the forward motion of the ram h, those cylinders andpistons on which a pressure does not act being nevertheless carriedalong and acting as guides for those cylinders and pistons which operateunder pressure in the manner above described.

WVhat I claim is- 1. In a hydraulic press, the combination of a seriesof working cylinders with inclosed pistons, a press-bar operatedthereby, steaminfluenced plungers adapted to directly enter thecylinders, a liquidinlet pipe communicatin with the cylinders, a valvecontrolling said pipe, an eXhaustpipe, and an outwardlyopeningspring-resisted check-valve in the exhaust-pipe and outside of thecontrolling valve, substantially as specified. l

2. In a hydraulic press, working pistons in connection with a press-barand steam-actuated plungers to operate said working pistons, means todistribute the steam upon said plungers, return-pistons and pipeconnections with a controlling-valve, a throttlingvalve upon said pipeconnections to regulate the pressure in the working cylinders, and acompressed-air vessel in connection with the return-cylinders,substantially as specified.

In witness whereof I have hereunto signed my name in the presence of twosubscribing witnesses.

BERTHOLD GERDAU.

Witnesses WILLIAM EssENwEIN, GEO. P. PETTIT.

